The CMB Infectious Disease Pathogenesis Section assisted Principal Investigators with experimental design, tissue collection and preparation, interpretation of histopathology findings, and assistance with manuscript preparation. CMB Research Support Specialists also provided technical expertise and support to NIAID Principal Investigators, assisting them with true cage to beachside support. Both pathology and technical proficiency resulted in numerous co-authorship opportunities. The CMB has completed the challenge of bringing a gnotobiotic facility on line. The gnotobiotic facility consists of 12 bio-exclusion units designed to keep the mice from becoming colonized with any adventitious microorganisms. Germ-free mice are free of all aerobic and anaerobic organisms with the possible exception of endogenous viruses. Breeding colonies and mice on study are maintained in semi-rigid isolators provided with HEPA-filtered air and autoclaved food, bedding, and supplies. Strict SOPs are followed to maintain the mice in a germ-free state. The CMB has an active Assisted Reproduction Technologies and Cryopreservation unit. Last year the ARTiC group had 68 sperm cryo request for 23 PIs and 2 requests for 1 PI inconjunction with Taconic. This year, the section had 30 requests from 14 PIs with 5 reuqeusts still in the pipeline. Last year, there were 40 Embryo Cryo requests from 14 PIs that resulted in 6607 empryos. There was 1 Taconic project from 1 PI that resulted in 312 embryos. This year, there were 8 requests from 8 PIs that resulted in 946 embryos and 2 Taconic projects that resulted in 240 embryos. There are 4 projects still in the pipeline for FY13. Last year there were 30 rederivation requests, this year there were 18. ARTiC ahd 3 requests for Transgenic mice in 2012 and 1 request in 2013. A mission of the Comparative Medicine Branch (CMB) is to provide support to the emerging and re-emerging infectious disease research conducted within the NIAID/DIR Animal Biosafety Level (ABSL) 3 facilities. Members of the Comparative Medicine Branch (CMB) along with a Division of Occupational Health and Safety (DOHS) representative have submitted a manuscript to the Journal of the American Association for Laboratory Animal Science (JAALAS) providing a background of laws, regulations, and an overview of programmatic requirements pertaining to the use of Select Agents. The manuscript was published in JAALAS in 2012.